1. Field of the Invention
The present invention relates to display devices and particularly to a high-resolution liquid crystal display device (LCD) that prevents display unevenness that results from the presence of regions where an alignment film is not formed.
2. Description of the Related Art
A typical LCD includes a thin film transistor (TFT) substrate, a counter substrate, and a liquid crystal layer placed between them. On the TFT substrate, pixels each having a pixel electrode, a TFT, and the like are formed in the form of a matrix. Images are produced by controlling the transmittance rate of light passing through the liquid crystal molecules on a pixel-by-pixel basis.
An organic passivation film is formed to cover the TFT, and a common electrode, the pixel electrode, and an insulating film for insulating these electrodes are formed on the organic passivation film. The organic passivation film is formed thick (e.g., 2 to 4 μm thick) since it is designed to serve as a planarizing film and to reduce stray capacitance. Because contact holes are formed in this thick organic passivation film, the depths and taper angles of the contact holes become larger, making it difficult for an alignment film to enter the contact holes.
Since the organic passivation film is formed thick, it has been proposed that the organic passivation film perform various functions. In JP-A-2003-177396, for example, concave and convex sections are formed in the organic passivation film at the display area, and a metal reflection film is formed on that uneven surface, thereby forming a Lambertian surface.
Also, in JP-A-2002-229062, the thickness of the organic passivation film is changed for each pixel (red, green, and blue pixels). By doing so, the thickness of the liquid crystal layer in each pixel is also made to change, whereby the optimal thickness of the liquid crystal layer can be achieved for each color pixel.